The process of reloading cartridges is most frequently practiced by the hobbyist who wants to tailor-make his own ammunition, or the frequent shooter who wants to save money by reloading his own cartridges. Reloading equipment can be purchased that will mount to a homeowners workbench, and reloading components (powder, primers, bullets) can be puchased for the specific purpose of being used with this reloading equipment.
The reloading equipment e.g. for reloading hand gun cartridges, includes a press that is typically adapted to be mounted to a workbench, but some versions are also of a hand held variety. The press includes a die holder, a cartridge holder, and mechanism for relative movement of the die holder toward and away from the cartridge holder. A plurality of dies are selectively mounted in the die holder and a cartridge is mounted in the cartridge holder. In sequence, the cartridge is forced into the successively mounted dies to;
(a) size the cartridge (prior firing will have caused some bulging); PA1 (b) remove and replace the spent primer; PA1 (c) expand the cartridge mouth to receive a bullet; PA1 (d) insert the bullet; PA1 (e) crimp the cartridge mouth around the bullet for secure holding of the bullet in the cartridge.
The above functions are typically accomplished with three dies, each of which has a generally cylindrical configuration. The first die has an inside shape that is the desired outside shape of the cartridge case (with some allowance for spring back of the cartridge case). Forcing the spent cartridge case into the die reshapes the outer configuration of the cartridge to fit the firing chamber of the firearm for which the cartridge is intended. This same die may include a pin that is inserted into the center of the cartridge as the cartridge is being re-sized, to impact the spent primer and force it out of the cartridge case.
A second die is oversized to easily surround the cartridge. An expander rod is carried inside the die. It enters the mouth of the cartridge and flares the mouth slightly for receiving a bullet.
A third die carries a bullet seating plug on the end of a rod. A bullet is placed into the flared mouth of the cartridge case and then the cartridge is inserted into the die. The seating plug engages and forces the bullet a desired depth into the case and then a crimping shoulder in the die engages and crimps the edge of the case around the bullet.